import * as _ from 'lodash'
class Greater {
  greeting: string;
  constructor(message: string) {
    this.greeting = message;
  }
  greet() {
    return _.join(["hello ", ' ' , this.greeting],'');
  }
}
let greeter = new Greater("world");
let button = document.createElement("button");
button.textContent = "say hello";
button.onclick = function () {
  alert(greeter.greet());
};
document.body.appendChild(button);
